The wife of a medicinal marijuana advocate who died suddenly while awaiting trial for drug charges claims police "harassment" of her husband put him under unbearable strain.

Stephen McIntyre was charged with supplying cannabis after police raided the Auckland offices of GreenCross, a group which dispenses low-grade marijuana to patients with prescriptions for legal synthetic versions of the drug.

His wife Reiko Yanai said McIntyre was initially upbeat about fighting the charges. But his mood changed after police officers turned up at the family home to check on bail conditions on July 16, eight days before his death.

Yanai claimed McIntyre, who was teaching guitar lessons at the time of the police visit, was threatened by the officers.

Yanai said the officers told her husband they could smell cannabis, asked him how he was going to plead and told him he could face further charges.

"Stephen was very upset by this experience," she said. "Stephen was a law-abiding, gentle man who was not used to aggressive police behaviour. He felt his security and privacy was unjustifiably violated. He felt scared and intimidated."

Father-of-two McIntyre, 47, was found dead at his home in Avondale, Auckland, on July 24. His death has been referred to the coroner.

Yanai said she planned to write to Police Commissioner Peter Marshall to complain about the force's actions.

Relieving Western Area Commander Detective Inspector Karyn Malthus said officers went to McIntyre's home to check he was living there, as his bail conditions stated.

Malthus said police could smell cannabis smoke within the address when the door was answered and chose to speak to him outside the address to "avoid causing him embarrassment".

Police chose not to pursue any charges over the cannabis smell, she said.

"Police inquired as to who Mr McIntyre's lawyer was so that any communication that might be required should go to the correct counsel. This is a normal police activity."

Blogger Martyn 'Bomber' Bradbury will today publish a letter on his Tumeke blog written by McIntyre immediately after the police visit on July 16.

"In retrospect, his friends now all see that the police turning up at his home at night and demanding to know what he was going to plead while threatening further charges had a terrible impact on Stephen," Bradbury said.

Drug Foundation chief executive Ross Bell said McIntyre was a "lovely guy" who had a "heart for helping people in need".

"He wasn't your typical cannabis law reformer, he was very pragmatic and a great advocate.

"I think Stephen had a real sense of what needed to be achieved because the people who are suffering and in pain do need to have advocates."

In its 2010 report into drug law, the Law Commission recommended a policy of non-prosecution against medicinal marijuana suppliers.

However, several GreenCross members have been charged with cannabis dealing in recent months. Last month a prominent member of GreenCross, Billy McKee, was sentenced to 12 months' home detention for supplying an undercover police officer.

Bell added: "It's at the whim of local police. I have seen lots of cases where the police have been willing to prosecute and some of those are very stark cases where a little bit of compassion would have gone a long way."